Pipe coupling

ABSTRACT

A pipe coupling for casting into concrete comprising a sleeve having external flanges near its ends for attaching the coupling to formwork and a collar and seal ring mounted on at least one end of the sleeve for sealingly connecting at least one pipe thereto.

This invention concerns pipe couplings.

If a pipe is to be cast into a concrete wall or floor, formwork for thecasting has to be altered to allow the pipe to pass through. That istime consuming and hence costly. Furthermore, the altered formwork willbe less re-usable. Additional expense arises in supporting the pipetemporarily during casting. Alignment of the pipe is time consuming anddifficult and often a source of error.

When alignment of a pipe to be cast in concrete is critical, the generalpractice is to make a hole in the concrete that is larger than the pipe.The pipe is then positioned later and secondary formwork used forcasting concrete about the pipe. Obviously, that involves additionaltime, work and expense. Furthermore, the additional concrete joints mayprovide regions of weakness through which leakages may occur. Finally,the concrete may have an inferior surface appearance because of the twocasting operations.

An object of this invention is to provide a way of casting pipes intoconcrete that avoids or at least mitigates against one or more of theabove-mentioned disadvantages.

According to the invention there is provided a pipe coupling, whichcoupling may itself be cast into concrete and to which one or more pipesmay be coupled.

A preferred pipe coupling of the invention comprises a sleeve having anexternal flange for attaching the coupling to formwork for concretecasting. The flange may be integral with or separable from the sleeve.The external flange may be spaced inwardly from one end of the sleeve,whereby a collar or the like may be connected thereto by means fordrawing the collar and flange towards each other for urging a sealingring into sealing contact with a pipe in or through the sleeve. In onepreferred embodiment the sealing ring is in a recess of the collar andis compressed between the collar and an end of the sleeve. In anotherpreferred embodiment, the sealing ring is in an annular recess of thesleeve end and is compressed therein by the collar.

Alternatively, an external flange may be at the end of the sleeve fordirect connection of a flanged pipe, valve or other piece of pipework tothe coupling by any suitable means such as by bolts or by welding.

Pipe couplings of the invention may be provided for single pipe couplingie., for one side of a concrete wall or floor, or may be provided forcoupling to opposite ends thereof. For a single coupling, the sleevepreferably increases in internal diameter from its intended outer end.For a double coupling, the sleeve preferably increases in internaldiameter from its ends towards its mid-region. That increase in internaldiameter provides some tolerance in alignment of a pipe to be insertedinto the coupling.

The external flanges of the couplings of the invention may be tapped forreceiving bolts or the like for attaching the couplings to concretecasting formwork. For coupling flanges that are inwards of the sleeveends packing pieces may be required between the flanges and theformwork. However, once the casting operation has been completed, theformwork may still be re-usable conventionally once any packing isremoved.

The external flanges may be provided with anchorages, such as anchorbolts, preferably on their inner faces.

The sleeves of the couplings of the invention may be provided with oneor more external puddle flanges. Furthermore, the sleeves may besteppedto accommodate pipes of different diameters at opposite ends of thecouplings.

The couplings of the invention may be fixed to formwork for concretecasting in any desired position. Then after casting and removal of theformwork, pipes may be coupled to or through the coupling and sealedabout their circumference.

This invention will now be further described, by way of example only,with reference to the accompanying drawings, in which:

FIG. 1 is a section through a first coupling according to the inventionin situ;

FIG. 2 is a section through a second coupling according to the inventionin situ; and

FIG. 3 is a section through a third coupling according to the inventionin situ.

Referring to FIG. 1 of the accompanying drawings, a first coupling 10 isshown cast into concrete 12. The coupling 10 comprises a sleeve 14 whichhas an increased internal diameter in its midregion compared to itsends. Spaced in from each end the sleeve 14 has a flange 16. Each flange16 is tapped on its outer face at 17 to receive bolts 18 for a collar 20which has an annular recess 22 for a rubber or like sealing ring 24 suchthat, as tightening the bolts, the collar 20 is urged towards the flange16 to trap and compress the sealing ring between the collar and the endof the sleeve 14. To the inward face of each flange 16 are securedanchor bolts 26.

The coupling 10 is cast into the concrete by first fixing to one side ofshuttering for casting a ring of material, such as plywood, of slightlylarger external diameter than the coupling flange and shaped to give achamfered outer edge shape as shown. The sleeve is then fitted to theshuttering with its flange up against the plywood ring and the sameoperation repeated for the opposite shuttering. The tapped holes 17 inthe flanges 16 may be used for bolts to fix the flanges to theshuttering. After casting the concrete, the shuttering is removed toleave the flanges 16 exposed. The pipes 30 to be fitted to the couplingcan then be packed into position and the sealing rings and collarsfitted and tightened. Because the diameter of the sleeve increasestowards its middle, the pipes 30 do not have to be fitted exactly inline, as the sleeve has space for the pipes to be out of line but stillsealed effectively. Alternatively, a single pipe length may be fittedthrough the sleeve.

As shown the sleeve 14 has the same diameter at each end. However, it ispossible for the sleeve to be stepped for coupling pipes of differentdiameter. In addition, the sleeve may be provided with an externalpuddle flange.

Turning to FIG. 2 of the accompanying drawings, a pipe coupling 40 isshown which is intended for connection to a flanged pipe or valve at oneend as well as for pipe coupling at its other end in the same way as thecoupling of FIG. 1. The coupling 40 comprises a sleeve 42 having alarger diameter at its mid-region than at either end, which provides adegree of tolerance for fitting a pipe 43 into the coupling. The sleeve42 has a flange 44 spaced inwardly from one end thereof and a flange 46at the other end thereof. The flange 44 is tapped on its outer face at48 to receive bolts 50 for a collar 52 which has an annular recess 54for a sealing ring 56 which is trapped between the collar and the end ofthe sleeve 42. When the collar and sleeve are drawn together by thebolts 50, the sealing ring is forced inwards to seal against the pipe 43which is inserted into the sleeve. The flange 44 may also have anchorbolts 60 on its inner face.

The flange 46 is intended for direct coupling of a flanged pipe or valvein a conventional manner, such as by means of bolts or by welding.

The coupling 40 is cast into concrete 62 in a similar way to thecoupling 10 except that the flange 46 is attached directly to shutteringso that after casting and removal of that shuttering, the flange 46 isflush with the concrete.

As with the coupling of FIG. 1, the sleeve 42 may be stepped foraccommodating pipes of different diameter at opposite ends and puddleflange may be provided on the outer surface of the sleeve.

Finally, in FIG. 3 of the accompanying drawings, a coupling 80 is shownthat is for use on one or both faces of a wall or floor. The coupling 80comprises a sleeve 82 having a widening cross-section from one end tothe other. In use the coupling 80 is cast into concrete so that thewider end of the sleeve is in inwards. The sleeve 82 has an externalflange 84 which is tapped at 86 for bolts 88 for securing a collar 90 tothe flange. The collar has an annular recess 92 for a sealing ring 94which in use is trapped between the collar 90 and the end of the sleeve82. The sealing ring when compressed between the collar and sleeve endexpands inwards to seal against pipe 96 inserted into the coupling.

The coupling 80 is cast into concrete in a similar way to the couplingof FIG. 1 of the accompanying drawings. Anchor bolts 100 may be providedon the inner face of the flange 84. Because the sleeve divergesinternally from its outer end, the pipe 96 does not have to exactly inline with the opening through the concrete but may be a few degrees offin any direction.

It will be appreciated that variations on pipe couplings other thanthose illustrated may be possible within the spirit and scope of thepresent invention.

I claim:
 1. A pipe coupling for casting into concrete and to which atleast one pipe is couplable, said coupling comprising a tapered sleevehaving an external flange spaced inwardly from one end of the sleeve forattaching the coupling to formwork for concrete casting, a collarmounted on the end of the sleeve, a seal ring mounted on the collar inalignment with the end of the sleeve and means connected to the flangefor drawing the collar towards the flange to urge the seal ring intosealing contact with the end of the pipe.
 2. A pipe coupling as claimedin claim 1, wherein the flange is integral with the sleeve.
 3. A pipecoupling as claimed in claim 1, wherein the flange is separable from thesleeve.
 4. A pipe coupling as claimed in claim 1, wherein said collarhas a recess and said sealing ring is in said recess of the collar andis compressed between the collar and the end of the sleeve.
 5. A pipecoupling as claimed in claim 1, wherein said sleeve has an annularrecess and said sealing ring is in said annular recess of the sleeve andis compressed therein by the collar.
 6. A pipe coupling as claimed inclaim 1 having an external flange at the end of the sleeve for directconnection of a flanged piece of pipework to the coupling.
 7. A pipecoupling as claimed in claim 6, wherein the sleeve increases in internaldiameter from its outer ends.
 8. A pipe coupling as claimed in claim 6,wherein the sleeve increases in internal diameter from its ends towardsits mid-region.
 9. A pipe coupling as claimed in claim 1, wherein saidmeans connecting includes the external flange being tapped for receivingbolts.
 10. A pipe coupling as claimed in claim 1, wherein said externalflange is provided with anchorages on the inward face.
 11. A pipecoupling as claimed in claim 10 further comprising at least one externalflange intermediate its ends.
 12. A pipe coupling for connecting theends of axially aligned pipes through a concrete wall, said couplingcomprising a sleeve having an external flange formed on said sleeve andspaced inwardly from each end of the sleeve, a collar mounted on eachend of the sleeve, a number of anchor bolts mounted in each of theflanges and extending through threaded openings in said collars wherebysaid collars can be drawn toward said flanges by turning the anchorbolts.
 13. The pipe coupling according to claim 12 including a sealingring positioned between said flanges and said collars for sealing theouter surface of the pipes in the coupling.
 14. The pipe couplingaccording to claim 12 wherein said sleeve decreases in internal diameterfrom its center to its outer ends whereby the pipes are free to movewithin said sleeve.
 15. The pipe coupling according to claim 12 whereinsaid collars overlap said sleeve ends.